1. Field of the Invention
The present invention relates to a fixing apparatus which fixes a developer image on a sheet.
2. Description of the Related Art
An image forming apparatus utilizing a digital technique, for example, an electronic copying machine has a fixing apparatus which applies a pressure to a developer image molten by heating to fix the image on a sheet.
The fixing apparatus includes a heating member for melting a developer, for example, a toner; and a pressurizing member which supplies a predetermined pressure to the heating member, and a predetermined contact width (nip width) is formed in a contact region (nip portion) between the heating member and the pressurizing member. A developer image on the sheet, molten by heat from the heating member, is fixed to the sheet which passes through this nip portion by pressure from the pressurizing member.
Moreover, a cleaning device for removing attached matters attached to the surfaces of the members, offset toner, paper powder and the like is disposed around the heating member or the pressurizing member.
For example, a fibrous cleaning sheet is allowed to abut on the surface of the heating member, an equal load is applied to both contact faces, toner, paper powder and the like are attached to the cleaning sheet, and accordingly the heating member is cleaned. Moreover, there is a cleaning device in which the cleaning sheet of a dirty portion is taken up, and the cleaning sheet of a new portion is successively unwound/released and allowed to abut on the surface of the heating member. In this case, since the toner or the like is attached to the whole contact face of the cleaning sheet with the heating member, and recovered, the removed toner or the like uniformly sticks to the whole contact face of the cleaning sheet.
When the cleaning sheet is taken up in this state, there is a problem that the toner or the like sticking to the cleaning sheet rubs the surface of the heating member in a contact portion between the cleaning sheet and the heating member, and the surface of a heating roller wears by friction. Therefore, the life of the heating member shortens, and it is difficult to maintain performance of the heating member for a long period of time.